1. Abo El-Nil, M. M., Hildebrandt, A. C.: Induction of geranium plants from anther callus. In Vitro 7, 399 (1971).
2. Clapham, D.: In vitro development of callus from the pollen of Lolium and Hordeum. Z. Pflanzenzüchtg. 65, 285?292 (1971).
3. Devreux, M., Saccardo, F., Brunori, A.: Plantes haploides et lignes isogeniques de Nicotiana tabacum obtenues par cultures d'anthères et tiges in vitro. Caryologia 24, 141?148 (1971).
4. Guha, S., Maheshwari, S. C.: Development of embryoids from pollen grains of Datura in vitro. Phytomorphology 17, 454?461 (1967).
5. Kameya, T., Hinata, K.: Induction of haploid plants from pollen grains of Brassica. Jap. J. Breeding 20, 82?87 (1970).